PB2617: ACTIVATED PLATELETS: A POTENTIAL EXTRA SOURCE OF ANTIANGIOGENIC FACTORS IN PREECLAMPSIA
Authors: Laura Mattana Dionisio, Giovani Marino Favero
Journal: HemaSphere (2023)

Topic: 32. Platelet disorders Background: Preeclampsia (PE) and other hypertensive disorders of pregnancy (HDP) are responsible for a substantial fraction of maternal and neonatal deaths. PE is a complex disorder whose etiology is not completely understood. Several factors are involved, such as endothelial dysfunction and platelet activation, which exert a key role in this disease. Considering the vascular aspects of PE, there is an imbalance between proangiogenic and antiangiogenic factors, characterized by increased levels of soluble FMS-like tyrosine kinase-1 (sFlt-1) and reduced placental growth factor (PlGF). The amount of sFlt-1 produced by the trophoblast is thought to be insufficient to justify the circulating levels of this factor in PE. Platelet indices have been studied in numerous diseases. There is evidence of the association between platelet indices with platelet activation and the incidence of HDP, which suggests that these could be helpful tools for the diagnosis and management of these patients. Aims: This study aimed to assess the platelet indices in HDP and their correlation with angiogenesis-related biomarkers. Methods: The groups for the study were: (C) (n=114), gestational hypertension (GH); (n=112); preeclampsia (PE) (n=42). The platelet indices included were platelet counts (PLT-I and PLT-F), mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT), platelet large cell ratio (P-LCR), and immature platelet fraction (IPF#, and IPF%). Serum levels of sFlt-1 and PlGF were assessed. Results: PLT-I, PLT-F, and PCT% were lower in PE, while MPV, PDW, P-LCR, IPF%, and IPF# were increased. There was a moderate positive correlation between sFlt-1 levels and MPV, PDW, and P-LCR (0.512, 0.457, 0.514, respectively (p < 0.001) Summary/Conclusion: Platelet indices can be potentially applied as additional tools for the diagnosis and management of HDP. Activated platelets may act as an extra source of sFlt-1 in PE. Table 1 – Platelet indices for pregnant patients. Median and interquartile range (IQR). - Control GH PE P* PLT-I (×109/L) 233 (195 – 271) b 219 (182 – 248) b 156 (130 – 193) a < 0.001 PLT-F (×109/L) 223 (195 – 265) b 220 (180 – 259) b 165 (135 – 199) a < 0.001 MPV (fL) 10.4 (9.9 – 10.9) a 11.1 (10.5 – 11.8) b 12 (11.2 – 12.9) c < 0.001 PDW (fL) 12.2 (10.6 – 13.2) a 13.8 (12.3 – 15) b 15.3 (13.5 – 17.8) c < 0.001 PCT (%) 0.23 (0.2 – 0.27) b 0.24 (0.21 – 0.27) b 0.20 (0.17 – 0.23) a < 0.001 P-LCR (%) 28.8 (23.6 – 33.6) a 33.6 (28.9 – 39) b 38.9 (33 – 44.9) c < 0.001 IPF% 3.9 (2.42 – 4.97) a 6.6 (3.98 – 9.53) b 11 (5.75 – 15.2) c < 0.001 IPF# (×109/L) 8.93 (5.45 – 11.8) a 13.8 (9.5 – 18) b 15.7 (11 – 26.1) b < 0.001 Different letters indicate significative difference between groups. Control: n= 114; GH: n=112; PE: n=42. *Kruskal-Wallis test with DCSF pairwise comparisons. PLT-I, impedance platelet count; PLT-F, fluorescence platelet count; MPV, mean platelet volume; PDW, platelet distribution width; PCT, plateletcrit; P-LCR, platelet large cell ratio; IPF%, immature platelet fraction - percentage; IPF#, immature platelet fraction - absolute count. PLT-I, PLT-F and IPF# are expressed in ×109/L. MPV and PDW are expressed in femtoliters (fL). PCT and P-LCR are expressed in percentages. Keywords: Pregnancy, Platelet activation, Angiogenesis, Anti-angiogenesis